Enhanced interfacial interaction of mesoporous N, S co-doped carbon supported WO3-WS2 for green and selective oxidation of alcohols

WO3-WS2 supported on mesoporous N, S co-doped carbon were prepared via one-step molten-salt strategy, and an enhanced interfacial interaction between metal and carbon was formed, which boosted the selective oxidation of benzyl alcohol to benzaldehyde. Under green conditions (solvent: H2O, oxidant: H2O2, no base-additives), 96.2 % conversion and 97.0 % selectivity were achieved within 2 h. It was found that N, S co-doped carbon with abundant mesopores served as an excellent support, the pyrrolic and graphitic N species of carbon provided main anchoring sites for metal nanoparticles. Additionally, the N, S co-doped carbon support could effectively promote the distribution of metal species, and thereafter induced the formation of metal–carbon interfacial interaction. Such advantages resulted in the satisfactory reusability (negligible activity loss after six cycles) and remarkable catalytic activity. The scavenger tests and EPR results disclosed that ·OH was the main oxidative species for this reaction. DFT calculations revealed that co-doping of N, S into carbon promoted the adsorption of benzyl alcohol, and the enhanced metal–carbon interaction reduced migration energy barrier of ·OH on catalyst surface. In sum, this work provided some new insights into the interfacial interaction of mesoporous carbon supported metal catalyst for boosting the selective oxidation of alcohols.